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structured-output SKILL.md skillA

structured-output from sigistry/marketplace is an agent skill: a SKILL.md folder an AI agent loads when a task calls for it.

Install it, pinned

mdr add sigistry/marketplace/structured-output@git:20260826.571bc2f

Pins git:20260826.571bc2f in mdr.lock. Pin the fingerprint instead.

Audit grade: A, 17 of 17 checks passed
Kind: SKILL.md skill
Repository: sigistry/marketplace
Path: plugins/llm-app-hardener/skills/structured-output/SKILL.md
Versions recorded: 2
Latest version: git:20260826.571bc2f, committed Aug 26, 2026
First version recorded: Jul 15, 2026
Size: 4,939 bytes
Repository stars: 3
License: MIT

This skill should be used when the user mentions "structured output", "json mode", "tool schema", "function calling", "json parse error", "response_format", "pydantic ai", "invalid json from the model", or "the model's JSON keeps breaking". It provides a methodology for getting reliably valid, schema-conformant structured output from LLMs across providers, plus a validate-and-retry fallback.

Collected from public GitHub. Every version is saved exactly as it was and never changes. Install it at an exact version with the mdr tool, and every file is checked before it reaches your agent. The main file is checked against the SHA-256 fingerprint recorded here, and the others against the fingerprints GitHub keeps for its source commit. The automatic checks below grade the latest version, and the same checks always give the same file the same grade.

What the file says

# Structured Output

## Purpose
Standardize how an LLM app gets machine-readable output it can trust. Asking a model for JSON in the prompt and calling `JSON.parse` / `json.loads` on the result fails on a non-trivial fraction of calls, a stray markdown fence, a trailing comma, a hallucinated field, an unescaped quote, and those failures surface as production exceptions on a code path that "worked in testing." Provider-native structured output (schema-constrained decoding or strict tool schemas) drops the invalid-output rate by one to two orders of magnitude. This skill gives the decision order: use the strongest native mechanism the provider offers, validate every response against a schema, and wrap it in a bounded retry-with-error-feedback loop.

## The reliability ladder (strongest first)
1. **Schema-constrained output**: the provider constrains decoding to your JSON Schema, *guaranteeing* the response validates. Anthropic `output_config.format` (`json_schema`), OpenAI `response_format: json_schema` with `strict: true`, Gemini/Vertex `responseSchema`. Use this whenever the model supports it.
…

Read the whole file at its exact version.

How to install

The exact contents, by fingerprint

mdr add sigistry/marketplace/structured-output@sha256:b3cd55cf1481924a

The line at the top of this page pins the label git:20260826.571bc2f, which is what most people want. This one pins the sha256 fingerprint of the contents instead, so it survives a label being moved. Either way the exact version is written to mdr.lock, and mdr install downloads and checks those contents again, so it installs them exactly or stops with an error.

Badge

[![mdr](https://markdownregistry.com/badge/art_js44ef76wcype47n.svg)](https://markdownregistry.com/a/art_js44ef76wcype47n)

5 badge image fetches in 30 days. What the badge shows.

Versions

The registry has recorded 2 versions of this file, between Jul 15, 2026 and Aug 26, 2026, about one every 42 days.

version	committed	commit	size	audit
git:20260826.571bc2f latest	2026-08-26	571bc2f	4,939 B	A	view · diff
git:20260715.6169119	2026-07-15	6169119	4,939 B	A	view

Audit of the latest version

A 17 of 17 checks passed. Fixed automatic checks with no AI involved, so the same checks give the same answer every run.

pass: Frontmatter block present
pass: Frontmatter declares a name
pass: Frontmatter declares a description
pass: Size between 200 bytes and 200 KB (4939 bytes)
pass: No zero-width or bidi control characters
pass: No instruction hidden inside an HTML comment
pass: No link to an exfiltration or paste host
pass: No credential-shaped string
pass: No instruction to send local credentials anywhere
pass: No text hidden with inline styles
pass: No prompt-injection phrasing
pass: No curl or wget piped into a shell
pass: No recursive delete of root, home or parent
pass: No instruction to read or print local credentials
pass: No base64 blob over 200 characters
pass: No link to a raw IP address
pass: No script tag

Source

GitHub

sigistry/marketplace · 3 stars · license MIT · pushed 2026-11-06 · branch main

API

GET https://markdownregistry.com/api/v1/artifacts/art_js44ef76wcype47n
GET https://markdownregistry.com/api/v1/resolve?ref=sigistry/marketplace/structured-output
GET https://markdownregistry.com/api/v1/blob/b3cd55cf1481924a4450061ebfed0bdfbb3507b33c2f22fa873de27572af290d

Your AI assistant does the legwork. You hear about the deals worth your word. Hand yours the standing instructions at modelranch.com and it joins the network that reads files like this one.

Guides: the SKILL.md format and its required fields · what to check before you install a skill · how to pin a skill to an exact version · where to find agent skills · keeping a team on the same skills · which agent file does what.

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